Bevacizumab as a treatment option for choroidal neovascularisation due to large optic nerve drusen in a 14-year-old girl

Purpose: To report the effects of a single intravitreous injection of bevacizumab for the treatment of secondary choroideal neovascularisation due to large optic disc drusen. Methods: A 14-year-old female patient with painless loss of vision in one eye presented with unusually large optic disc drusen and juxtapapillary choroidal neovascularisation with subretinal hemorrhage. She was treated with a single intravitreous injection of bevacizumab. Results: Visual acuity increased from 20/100 to 20/25 within 4 weeks after injection and remained at this level during the 12-month follow-up period. Conclusions: Bevacizumab is a possible primary treatment option for secondary choroidal neovascularisation due to large optic disc drusen in children as an alternative to other more invasive or complex procedures.


Introduction Patient and methods
Optic disc drusen (ODD) are remnants of mucopoly-A 14-year-old female patient presented at our clinic with saccharides from degenerated ganglion cells which calcify painless loss of vision in her left eye, slowly progressing and accumulate within the optic nerve head over time for over one week. VA had dropped to 20/100 on the af- [1]. The incidence of ODD in children is reported to fected side, whilst retaining 20/20 vision on the other be 0.4%. They seem to become visible around the age eye. Intraocular pressure was within physiological limits. of 12 [2]. Further examination showed a blurry and prominent optic With increasing size, they raise the optic disc, blur out disc with an adjacent decent subretinal hemorrhage the edges, and lead to abnormal vascular branching and ( Figure 1). The contralateral optic disc also displayed a formation of cilioretinal vessels, causing hemorrhages slight blurriness, but there was no sign of subretinal [3]. This destruction of the parapapillary anatomy can hemorrhage. Optical coherence tomography (OCT) showed cause visual field defects and the formation of choroidal the formation of a juxtapapillary cystoid macula edema neovascular membranes (CNVM) that lead to decreased (CME) with subretinal scarring. Corresponding to this, the visual acuity (VA) [4].
intravenous fluorescein angiography (IVFA) displayed Because of the rare occurrence of CNVM associated with leakage at this location throughout all phases, followed ODD, different therapeutic approaches have been re-by pooling. Additionally, ultrasound was carried out, which ported only via small case studies. Next to surgical re-exposed unusual large and deeply located ODD on both moval [5] and photodynamic therapy [6] or laser coagu-eyes. These were however significantly larger and closer lation [7], intravitreous injection of anti-VEGF agents to the optic disc's surface on the affected left eye. seems to be an option with long-term satisfying results After discussing the potential treatment options and risks [8], [9], [10], [11].
with the child's parents, a single intravitreous injection of 1.25 mg bevacizumab was given under general anesthesia.

Results
VA increased to 20/25 over a period of 4 weeks. The cystoid edema as well as the subretinal hemorrhage re-solved, leaving a small subretinal scar and a mild dissociation of the pigment epithelium ( Figure 2). The patient and her parents were instructed to perform self-tests using the Amsler grid and to report to the clinic, should 2/3 GMS Ophthalmology Cases 2020, Vol. 10, ISSN 2193-1496 any deterioration occur. Further appointments were scheduled regularly at an interval of 4 weeks for 6 months overall, then followed by examinations every 12 weeks. During this phase, the VA fluctuated between 20/25 and 20/20. There was no recurrence of CME or subretinal bleeding during the follow-up period.

Discussion
In the last decade, intravitreal injections of anti-VEGF agents have proven to be an effective therapy for a variety of retinal and especially macula diseases, for example neovascular age-related degeneration and diabetic macular edema. Disease-adapted guidelines were promoted and published for the initial therapy as well as for the long-term intervention [11], [12], [13]. Because of the rare incidence of CNVM secondary to ODD, especially in children, there are no established or widely accepted treatment regimens until today. In our case, the patient showed a complete remission after only one injection. The options of further injections at a fixed interval, or of close observation and treatment only if required were discussed with the patient and her parents. The decision was made towards short-interval follow-up examinations. Compared to the results of anti-VEGF therapy that have been published in other case series, the juvenile secondary CNVM in our case responded better to this form of treatment. Until today, no further injections were necessary, confirming our choice of treatment plan.